Time-delay relay arrangement



INVENTOR OSKAR LUHN ATTORNEY Flled July 13 1949 O LUHN TIME-DELAY RELAYARRANGEMENT May 15, 1951 Patented May 15, 1951 OFFICE TIME-DELAY RELAYARRANGEMENT O'skar Liihn, Hunfeld, Germany, assignor to HerbertClemmens, Los Angeles, Calif.

Application July 13, 1949, Serial No. 104,579 In Germany February 14,1949 8 Claims.

The present invention relates to a time-delay relay arrangement in whichthe making of a connection may be effected by means of a very weakcurrent. This arrangement permits for instance that after a signal hasbeen produced by means of a very weak current, the signal is againautomatically disconnected after a predetermined period of time by meansof a time delay device such as a thermo-bimet'al or the like after apredetermined period of time depending on the setting of the deladevice. The breaking may of course be effected also manually. The use ofthe relay arrangement is extremely versatile. It may serve for exampleas telephone call repeater for connecting a heavy power horn or a heavypower bell of very great loudness. It is, however, also possible toconnect with the help of the relay arrangement a repeater so that thetransmission of certain communications may be effected by telephone andloudspeaker. The time-dela relay may also be used in conjunction with amidget transformer connected in the circuit of a push button switch orthe like, for staircase illumination or similar purposes in which casesit is the matter to effect an automatic cut out after a predeterminedperiod of time.

One form of embodiment of the invention is diagrammatically illustratedin the accompanying drawing by way of example.

The time-delay relay arrangement comprises the switching relays A and Beach of which being provided with a making winding i. e. an attractionwinding I and 2 respectively and a compensating winding 3 and 4respectively. The relays further consist of the'pole shoes 5 or 6, thearmatures I and 8, the contacts 9, I0, II and I2, I3, I4 respectively.The time-delay arrangement in addition comprises a thermo-bimetal I5with heating winding I6 and the contacts H and I8 with which the bimetalcontact I9 has electric contact corresponding to its position. 2Iindicates a resistor for the compensating winding 4, 22 is a powersource, 23 a current load (e. g. a lamp), 24 is the connection of thecontrol winding or compensating winding 3, through which the relayarrangement is caused to respond.

If a weak alternating current e. g. of the magnitude of 0.1 ma. and 4volts is applied to the terminals 24 i. e. to the compensating winding3, the remanence in the armature 8 and in the pole shoe 6 which has beenproduced by means of the winding I and retains the armature on the poleshoe 6 owing to the adherence, is neutralized. The neutralization of theremanence has as a result the release of the armature. The release ofthe armature 8 will close contacts 9, IE] and the source 22 will causecurrent to fiow through the contact springs connected to contacts I0 and9, the winding 2, the contacts I-2, I3 and back to 22. The armature I isaccordingly attracted and the contact spring I3 separated from I2whereupon the armature still adheres to the pole shoe 5 owing to theremanence in the relay B, so that the circuit will remain interrupted.Simultaneously with the establishment of the contact between I0 and 9the power source 22 is connected through the contacts I0, 9 and theseries resistor 26, the heating resistor I 8 and its thermo-bimetalstrip 55 whereupon the expansion of the latter in the direction of thecontact I8 is effected. Simultaneously therewith the power source 22 isconnected through the contacts I3, I4 to the current load 23 as a resultof the closing of the contacts l3, I l effected by the attraction of thearmature I. According to the adjustment of the time-delay conditioned bythe thermo-bimetal the contact I!) is moved towards the contact I8. Inthe moment of a contact between I8 and I9 the current from the source 22flows through the thermo-bimetal I5, the contacts I9 and I8, the windingI, the contacts 9, II] and back to the source 22. The current flow inthe winding I has as a result that the armature 8 is attracted by thepole shoe 6 in consequence of which the contact spring I0, which owingto the current conducted through the winding 3 following the precedentrelease of the armature 8 has made a connection with the contact 9, isagain lifted and thus the current of the source 22 is switched off themaking winding I.

After this procedure the one terminal of the power source 22 is againapplied through the contact spring ID to the contact II and thus to theone end of compensating winding 4, which on the other hand is connectedto the contact I? through a resistor 2I. In consequence of theinterruption of the contacts 9, l0 simultaneously the heating resistorI6 is again disconnected, so that the thermo-bimetal (contact) whichowing to the influence of heat has connection with the contact ispermitted to move back to its initial position.

If after a predetermined period of time the contact I9 is in connectionwith the contact H, the circuit including the compensating winding isclosed, which has as a result that owing to the weak current of thesource 22 flowing through the compensating winding the armature I isreleased in consequence of the neutralization of the remanence in therelay B and takes again the contacting position shown.

After the release of the armature I the circuit 23 is again interruptedfollowing the separation of the contacts I3, I4. If e. g. after theattraction of the armature 8 following the closing of the contacts I8,I9 a new current pulse is generated or if the supply of current to thewinding 3 continues, the armature is immediately released again. If,after the closing of the contacts 9, I!) the armature is again attractedowing to the current of the source 22 flowing through winding I, thesaid armature will continue to oscillate at a certain rate until theinfluence of the control current on the winding 3 ceases. The contacts9, being permanently closed the heating winding l6 receives currentpulses so that a contact between the contacts l9 and I1 is not possibleunless the movement of the armature continues 1. e. as long as thecurrent continues to excite the winding 3. The bimetal contact I9continues to have connection with the contact [8 owing to its expansion,so that the current load 23 is not influenced by the movement of thearmature of the relay A.

In making use of the relay arrangement for controlling purposes athermo-bimetal, a contact moving coil or any other appliance of very lowdirecting force may be connected in the circuit of the compensatingwinding 3, whereby a weak current is released to be applied to thecompensating winding 3.

I claim:

1. A time-delay relay arrangement responsive to very weak signalcurrents, comprising a first and a second relay; exciting windings forsaid relays; compensating winding for said first relay; 9.thermo-sensitive deflecting device; heating element for said deflectingdevice; a load circuit operatively associated with said second relay; asource of energizing current for said relays; contact means operativelyassociated with said first relay and connected in circuit with saidenergizing current source, the energizing winding of said second relayand said heating element; means for impressing a source of signalcurrent across said compensating winding to cause said first relay torespond to operate said contact means thereby causing energization ofsaid heating element to cause deflection of said thermo-sensitivedeflecting device and causing energization of the energizing winding ofsaid second relay to operate said last-named relay to close said loadcircuit; and means including contact means operatively associated withsaid deflecting device and in circuit with the energizing winding ofsaid first relay to cause said last-named relay to assume its originalposition after a predetermined deflection of said deflecting device inresponse to energization of said heating element,

2. A time-delay arrangement according to claim 1, contact meansoperatively associated with said second relay, said last-named contactmeans being in circuit with said load to close said load circuit uponoperation of said second relay.

3. A time-delay relay arrangement according to claim 2, compensatingwinding for said second relay, a pair of contacts closed when saiddeflecting device is in normal undeflected condition, said last-namedcontacts being in series with said last-named compensating winding, saidcontact means operatively associated with said first relay beingconnected to said last named compensating winding thereby causingenergization of said compensating winding of said second relay when saiddeflecting device is in undeflected condition and said first relay is inresponded condition, thereby causing said second relay to release.

4. A time-delay relay arrangement according to claim 3, a pair ofcontacts operatively associated with said deflecting device closed uponsaid deflecting device being deflected a predetermined amount, saidlast-named contacts beingin circuit with the energizing winding of saidfirst relay, said first-named relay being arranged to remain in operatedcondition after deenergization of the energizing winding thereof, saidlastnamed relay being released upon a Weak current of and operated uponsaid deflecting device being deflected to close said last-named pair ofdeflecting device contacts, thereby energizing the energizing winding ofthe first relay.

5. A time-delay relay arrangement according to claim 4, said first relayhaving front contacts and back contacts, said back contacts of saidfirst relay being in circuit with said source of energizing, said backcontacts being closed upon a weak signal current flowing through thecompensating winding of said first relay, thereby releasing saidlast-named relay, the closing of said back contacts closing the circuitto the heating element for said deflecting device and simultaneouslyclosing the circuit for the energizing winding of said second relay tocause said second relay to operate thereby closing said load circuit.

6. A time-delay relay arrangement according to claim 5, the second relaybeing adapted to remain in operated position by the remanence in thearmature thereof after having been operated by current flow through theenergizing winding thereof, the front contacts of said first relay beingin circuit with said compensating winding of said second relay toenergize said compensating Winding of said second relay and to cause therelease of the second relay upon operation of said first relay.

'7. A time-delay relay arrangement according to claim 6, a currentlimiting resistor in series with the compensating winding of said secondrelay.

8. A time-delay relay arrangement comprising a relay, said relay beingof the type remaining in operated position after once being energized byi'emanence in the magnetizing circuit thereof, a pair of windings forsaid relay, one of said windings being adapted to be connected to asource of weak signal current, the flow of signal current through saidone winding overcoming said remanence to release said relay, a source ofenergizing current, energizing winding for said relay, contact meansoperatively associated with said relay adapted to connect one side ofsaid energizing winding to one side of said source when said one relayis in released condition, a thermal deflecting device, heating elementfor said deflecting device, contact means operatively associated withsaid deflecting device, said last named contact means being open whensaid deflecting device is in undeflected condition and closed when saiddeflecting device is deflected a prededetermined amount, means forenergizing said heating element when said one relay is in releasedcondition to heat said deflecting means to cause said deflecting meansto deflect and after a predetermined period of time to close saidlastnamed contact means, said last-named contact means being in circuitwith the other side of said energizingwinding and with the other side ofsaid source of energizing current to cause energization of said windingupon closure to operate said relay.

OSKAR LiiHN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,636,900 Darker July 26, 19272,170,694 Perry Aug. 22, 1939 2,441,984 Armstrong May 25, 1948 2,463,469Sherwood Mar. 1, 1949

